From: ts <decoux@...>
Date: 2001-03-13T02:28:35+09:00
Subject: [ruby-talk:12515] Re: rb_ary_each and hash

>>>>> "U" == User Tcovert <tcovert@sahuagin.ne.mediaone.net> writes:

U> is there an example of how to use the rb_ary_each(VALUE) function. I
U> know how to use it in ruby, but not sure how that would work in c. 

 I've not understood for Array you can make :

   for (i = 0; RARRAY(ary)->len; i++) {
       /* 
          do what you want with RARRAY(ary)->ptr[i]
       */
   }


U> I have a hash of string-values, I'd like to make a c array of cstr's, I
U> was wondering how I can iterate through the hash to pull out all the
U> values. I can figure out how I would do this with an array(I think) but
U> looking in ruby.h and internal.h I can't see any operators that would
U> work with the Hash. I know it mixes in enumerable, but I'm not sure how
U> that affects the c layer. 

 Here a little, and stupid, example to iterate with rb_iterate()

pigeon% cat tt.c
#include <ruby.h>
 
static VALUE
tt_puts_i(obj, tt)
    VALUE obj, tt;
{
    VALUE key, value;
 
    key = rb_ary_entry(obj, 0);
    value = rb_ary_entry(obj, 1);
    rb_warn("%d %d %d", NUM2INT(key), NUM2INT(value), NUM2INT(tt));
    return Qtrue;
}
 
static VALUE
tt_hash(hash, obj)
    VALUE hash, obj;
{
    rb_iterate(rb_each, hash, tt_puts_i, INT2FIX(12));
    return Qtrue;
}
 
void Init_tt()
{
    rb_define_method(rb_cHash, "toto", tt_hash, 0);
}
pigeon%

pigeon% ruby -rtt -e '{12 =>12, 24 => 34}.toto'
-e:1: warning: 24 34 12
-e:1: warning: 12 12 12
pigeon% 



Guy Decoux